Formula One carmakers say they have made significant progress in talks with commercial supremo Bernie Ecclestone to end the threat of a rival series from 2008.
A spokesman for the Grand Prix Manufacturers' Association (GPMA) confirmed the manufacturers would meet Ecclestone again before Sunday's season-opening Bahrain Grand Prix, but played down expectations that an agreement could be announced in days.
"We will of course meet with the commercial rights holder this weekend," he said.
"Significant progress has been made and we hope to address several of the outstanding issues.
"But it's too early to predict any outcome. We don't want to speculate but things are moving in the right direction," added the spokesman.
The five GPMA members are world champions Renault, BMW, Honda, Toyota and DaimlerChrysler's Mercedes. The first four all own teams while Mercedes have a 40 percent stake in McLaren.
They are demanding a bigger share of the revenues from the billion dollar business, greater transparency in the running of the sport and equal treatment for all.
The GPMA, led by BMW board member Burkhard Goeschel, have said they will launch their own championship from 2008, when an existing commercial agreement expires, if their demands are not satisfied.
Ecclestone, who represents commercial rights holders CVC after they bought out two of the three banks controlling Formula One, has agreed terms with six teams so far, including former champions Ferrari and Williams.
The 75-year-old Briton was quoted last week as saying that he expected all the issues to be settled before the race in Bahrain.
"What we can agree on the technical side is dependent on how much money they want to save but they will save a huge amount without adversely affecting the technical excellence of F1," he told the Daily Express newspaper.
"We can all see the benefits of cutting costs while continuing to allow some areas of research and development and I think there is a mood of conciliation now," he added.
"They will certainly earn a lot more money on the commercial side, double what they got before."